Tamsulosin: What You Need to Know About This Urinary Medicine
Tamsulosin is a prescription medicine that relaxes muscles around the prostate and bladder neck. It is most often used to improve urine flow and reduce symptoms of an enlarged prostate, such as difficulty urinating, a weak stream, and frequent or nighttime urination.
Tamsulosin can make urinating easier, but it may also cause dizziness or fainting, especially when standing up. Take it only as prescribed and ask your doctor or pharmacist about personal risks and interactions.
Key facts at a glance
- ATC
- G04CA02
- Generic
- Tamsulosin
- Class
- alpha-blocker
- Brands
- Flomax
- Availability
- rx
- Pregnancy
- B
- Lactation
- caution
- Half-life (h)
- 14
- Onset (min)
- 240
- Duration (h)
- 24
- Routes
- oral
- Forms
- capsule
- Regions
- CN, US, EU, JP
- Monitoring
- orthostatic-hypotension
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 0.4mg once daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 0.2mg once daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 0.4mg once daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
7 groupspregnancy
first trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
third trimesteravoid
avoid use near term due to potential effects on newborn
fetal monitoring and assessment of newborn
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
breastfeedingavoid
discontinue breastfeeding or avoid drug; not recommended during lactation
monitor infant for adverse effects
Use of this medication in this population requires careful consideration of risks and benefits.
geriatric
elderlystart at low end of dosing range
use with caution due to increased sensitivity to orthostatic hypotension
monitor blood pressure and for signs of hypotension
Use with caution and monitor for adverse effects.
pediatric_age
children adolescentsnot recommended
not approved for use in patients under 18 years
not applicable
Use of this medication in this population requires careful consideration of risks and benefits.
renal_impairment
severe renalno initial dose adjustment needed but monitor closely
use with caution in severe renal impairment (CrCl less than 10 mL/min)
monitor renal function and blood pressure
Use with caution and monitor for adverse effects.
hepatic_impairment
severe hepaticno specific dose adjustment established
use with caution in severe hepatic impairment
monitor liver function and blood pressure
Use with caution and monitor for adverse effects.
Statistics and clinical data
FDA approval year
FDA approval for treatment of benign prostatic hyperplasia
Drug class
Pharmacological classification based on mechanism of action
Primary indication
Main therapeutic use for symptom relief of enlarged prostate
Mechanism of action
Blocks alpha-1A receptors in prostate and bladder neck to improve urine flow
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 22, 2026. · Read our editorial policy